This invention relates generally to lubrication systems for drive units and more particularly to seals used with such systems.
Many types of drive units for transmitting power are well known and are widely used in industrial applications, such as in power take-off units, and in vehicular applications, such as in axles. Lubricant flow over the drive unit components lubricates and helps dissipate heat. For example, lubricant flowing rapidly across the bearings and gears of an axle can absorb heat therefrom and transfer it to the housing, which often has fins or other heat dissipating devices rendering it more capable of such heat dissipation.
With the ever increasing size of drive units used in industrial and vehicular applications, as for example heavy duty truck axles, lubricant circulation becomes increasingly difficult. Increasing speed and load carrying requirements of modern vehicular and industrial drive units have increased the stresses to which these drive units are exposed and have magnified the lubrication problems.
At least one lubricant circulation system, that disclosed in U.S. patent application No. 831,588, assigned to Dana Corporation, the disclosure of which is incorporated herein by reference, has significantly advanced the state of the art by providing a pressurized system for forcing lubricant to critical drive unit components. Unfortunately, previously known seals have not been entirely satisfactory in such a pressurized system.